Final answer:
People are best at predicting the valence of their emotions, knowing whether they will experience something as positive or negative. They are less accurate, however, at predicting the severity and duration of their emotions, often overestimating how long emotional reactions will last.
Step-by-step explanation:
People often believe they can predict their emotions, including the valence (whether they are positive or negative), the severity (intensity), and the duration (how long they will last). However, empirical research in psychology suggests that people are reasonably good at predicting the valence of their emotions; they know when they are likely to experience positive or negative emotions. However, people are less accurate at predicting the severity and especially the duration of their emotions, often overestimating how long their emotional reactions will last.
One relevant concept in emotional prediction is the 'affective forecasting error,' where individuals misjudge the future impact of events on their emotional states. This typically manifests as people thinking they will feel an emotion more intensely and for a longer duration than they actually do. Thus, when it comes to predicting emotions, people are most successful at determining the valence, but not as adept at forecasting the severity or duration of their emotional experiences.